• • Adding 3% AMRM increased cumulative methane yield to 633.9 mL/g VS, a 175.1% improvement over control and 55.2% over raw RM, with VS removal reaching 75.1%, demonstrating significant enhancement in AD efficiency.
• • Acid modification increased AMRM's specific surface area by 347% relative to RM, enabling rapid adsorption of VFAs, especially propionic acid, as evidenced by adsorption kinetics (Qe of 40.234 mg/g for AMRM vs. 25.416 mg/g for RM in pseudo-first-order model).
• • AMRM enriched hematite (Fe2O3) content, which elevated ETS activity and coenzyme F420 levels, indicating enhanced DIET between syntrophic bacteria and methanogens, a critical mechanism for stable methane production.
• • The dual-pathway synergy—physical adsorption in the initial phase and electron transfer in the long term—effectively mitigated acid stress and sustained high-rate methanogenesis, offering a robust solution for high-organic-load FW treatment.